13957809 has 4 divisors (see below), whose sum is σ = 18610416. Its totient is φ = 9305204.

The previous prime is 13957789. The next prime is 13957817. The reversal of 13957809 is 90875931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13957809 - 2⁸ = 13957553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13958809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2326299 + ... + 2326304.

It is an arithmetic number, because the mean of its divisors is an integer number (4652604).

Almost surely, 2^13957809 is an apocalyptic number.

It is an amenable number.

13957809 is a deficient number, since it is larger than the sum of its proper divisors (4652607).

13957809 is an equidigital number, since it uses as much as digits as its factorization.

13957809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4652606.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 13957809 is about 3736.0151230957. The cubic root of 13957809 is about 240.7718725309.

The spelling of 13957809 in words is "thirteen million, nine hundred fifty-seven thousand, eight hundred nine".